Interesting questions. In the the main cave I survey, we use a value 
(called "share") between 0 and 1 for each shot (normally we use 0, 0,5 
and 1 and a very few times 0,3 and 0,7). If the the share = 0,5, means 
that only 50 % of the length is used when we calculate the length of the 
cave. The total length of the cave is therefore 24439 meters. The length 
of the centerline is 25703 meters. We calculate the length in Excel, and 
the depth in Therion.

Normally, we do not exclude any length at proper crossroads (share=1,0), 
meaning that we would have included the red parts in the length of the 
cave in the crossroad example. Our argument to do so is that a person 
has to walk that distance if he walks in the center of the passage. (A 
cave is a 3D-void and, strictly speaking, doesn't have any length, - but 
we humans would like to think that is has ... :-))

Regards

Torstein

Den 21.02.2012 21:17, skrev Maximillian Dornseif:
> I might understand something wrong, but it seems to me, that
> what is called `cavelength` in Therion is actually the length of all 
> centerlines.
>
> This might correspondent to the cave length in straight caves but 
> certainly not in labyrinth like caves.
>
> I was told about the "Kluterthöhle" in germany which was surveyed in 
> the 60ies to ca. 5900 m and then
> resurveyed and recalculated - to have only a length of 5200 m or so.
>
> This is for on the one hand a problem with circular shots inside big 
> rooms, like http://filez.foxel.org/3s3H0d2X361A0K222Z3N
>
> An other problem are crossroads like 
> http://filez.foxel.org/1t0C0r2Q011i0g1L0i00 where you can't young the 
> shared area of two passages twice but must - at least to what I have 
> been thought - deduct some part of the centerlines: in the following 
> picture I have marked the parts being considered cavelength yellow and 
> the centerlines not counting as part of the cavelength red 
> https://img.skitch.com/20120221-jhraj625isy8j1i9naxiki3b76.png
>
> Certainly I'm not the first person stumbling about this.
>
> What is the preferred way to approach the calculation of cave lengths?
>
> Regards
>
> Maximillian
>
>
>
> Image 2012.02.21 21:06:44.png20120221-jhraj625isy8j1i9naxiki3b76.png
>
>
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